petraeus' friend says it started around november 2011, two months after he took over the cia. an important point since he could be tried under military law for adultery. >> my understanding from him is that the affair did not begin when he was in the army. >> reporter: many who know the general suspect it did begin in afghanistan. it was september 2010 that broadwell made her first of six visits to petraeus in the war zone after being granted extraordinary access to write the book about him. >> and when i was in kabul, we would do a lot of interviews on runs. for him i think it was a good distraction from the war. >> reporter: question two. when did the fbi get involved? it was around may or june that the fbi was tracing those threatening e-mails sent to petraeus' friend jill kelly. kelly mentioned harassing e-mails to petraeus herself and the belief that they were from broadwell. officials say broadwell turned over her competitor to the fbi where they found a trove of explicit e-mails between petraeus and broadwell. the fbi does not believe petraeus gave any classified inform